In vivo fracture of an extruded polymethylmethacrylate intraocular lens loop

Area of Science:

• Ophthalmology
• Materials Science

Background:

• Anterior chamber intraocular lenses (AC IOLs) are used to restore vision after cataract surgery.
• Semiflexible, closed-loop AC IOLs made of polymethylmethacrylate (PMMA) are common implants.

Observation:

• A 72-year-old female experienced a fracture of the inferior loop of her PMMA AC IOL at two sites.
• The inferotemporal portion fractured at 25 months, and the nasal portion at 55 months postoperatively.
• The patient reported no significant eye trauma or excessive eye rubbing.

Findings:

• Fractures occurred near the loop-optic junction of the AC IOL.
• The fractured loop intermittently contacted the cornea, leading to endothelial damage and corneal edema.
• Visual acuity improved to 20/30 after the explantation and exchange for a different AC IOL style.

Implications:

• This case highlights a potential material failure mode in PMMA AC IOLs.
• Loop fractures can cause secondary ocular complications, including corneal damage.
• Careful material selection and design are crucial for long-term AC IOL safety and efficacy.